What is a roof pitch?
- A roof pitch refers to the steepness of the roof and can also be referenced as the slope, incline or angle. Roofers typically refer to it as a pitch and can be found by factoring the rise over a 12 inch run.
Why figure what your roof pitch is?
- Helps determine what materials are suitable for your roof. For example, a roof with a pitch of 1 cannot use metal shingles.
What is the multiplier?
- A flat roof has a pitch of 1, meaning the material needed is 1 times the size of the roof. Based on the pitch, you can use the multiplier to determine the amount of material needed for a roofing project.
After safely measuring your roof to discover the pitch, you can use the graph below to calculate your roof pitch in degrees and multiplier.
| PITCH | ANGLE | MULTIPLIER |
| 1/12 | 4.8° | 1.003 |
| 2/12 | 9.5° | 1.014 |
| 3/12 | 14.0° | 1.031 |
| 4/12 | 18.4° | 1.054 |
| 5/12 | 22.6° | 1.083 |
| 6/12 | 26.6° | 1.118 |
| 7/12 | 30.3° | 1.158 |
| 8/12 | 33.7° | 1.202 |
| 9/12 | 36.9° | 1.250 |
| 10/12 | 39.8° | 1.302 |
| 11/12 | 42.5° | 1.357 |
| 12/12 | 45.0° | 1.414 |
| 13/12 | 47.3° | 1.474 |
| 14/12 | 49.4° | 1.537 |
| 15/12 | 51.3° | 1.601 |
| 16/12 | 53.1° | 1.667 |
| 17/12 | 54.8° | 1.734 |
| 18/12 | 56.3° | 1.803 |